Perhaps you should try some spelling variations:
pham chuc » pham duc, pham huu, kham chua
pham thuc » phap thuc, nham thuc, pham thu
cau tren » cu tren, dau tren, ca tren
thu nang » thi nang, thu hang, thu bang
danh sai » dung sai, danh bat, danh dau
sach thu » sach thue, sach thieu, sach tham
sai cau » lai chau, mai chau, hai chau
va danh » va dinh, va dan, va hanh
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
hieu ve » hieu van
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach thu nang x hoi. ((hieu ve) or (hieu va)) ((pham thuc) OR (pham chuc)) va danh sai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu nang x hoi. ((hieu ve) OR (hieu va)) ((pham thuc) OR (pham chuc)) va danh sai cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thu nang x hoi. ((hieu ve) or (hieu va)) ((pham thuc) OR (pham chuc)) va danh sai cau tren".
• Adding a wildcard symbol may retrieve word variants: tu sach thu nang x hoi. ((hieu ve) or (hieu va)) ((pham thuc) OR (pham chuc)) va danh sai cau tren*.